Ventilator Associated Pneumonia (VAP) is the second most common Hospital Acquired Infection (HAI) in the United States. Based on national health care statistics, it has been projected that between 9% and 25% of patients in intensive care units (ICU) will acquire pneumonia via mechanical ventilators while hospitalized and of these cases over 25% will die. The incremental cost of treating patients who become infected by assisted respiratory systems is significant and is estimated to be between $40,000 to $60,000 US dollars.
VAP principally affects patients who are intubated with endotracheal devices (typically in the ICU). In the process of intubation, a flexible tube is inserted into the trachea in order to maintain an open airway. Intubation is frequently performed on critically injured or critically ill patients to facilitate ventilation, including mechanical ventilation, of the lungs.
Passing a tube through the mouth (or nasal passage) and vocal cords into the trachea is the most common method of intubating. In a less common practice (used almost exclusively in emergency circumstances) a tracheotomy is performed where an incision on the external aspect of a patient's neck which forms a direct airway in the trachea and a tube is inserted therein.
After the trachea has been intubated, a balloon cuff is typically inflated just above the distal end of the tube—such that there is a tracheal/endotracheal tube segment superior to and inferior to the balloon. The balloon surrounds the outer perimeter of the tracheal/endotracheal tube and when inflated it contacts the inner walls of the trachea thereby securing the tube in place and protecting the lungs from receiving undesirable material such as stomach acid.
The primary cause of VAP is due to the flow of infected natural secretions (mucins) from the nasal passages and the oral region into the lungs. Nasal and oral secretions generally collect above the balloon in the subglottic region (superior to the balloon). If they are not appropriately drained, they can bypass the balloon and flow into the lungs.
This problem can be compounded with the flow back of infected mucins that are generated below the balloon (inferior region). Furthermore, mucins that are generated in or near the lungs and are expelled by coughing can accumulate below the balloon and flow back into the lungs exacerbating the infections.
While it is possible to isolate secretions in the subglottic region (the area between the balloon and the mouth) with a tracheal or endotracheal tube cuff- balloon, inevitably, unless these infected secretions are systematically and periodically removed, some will by-pass the balloon and flow into the lungs. Furthermore, as previously mentioned, secretions generated between the balloon and the lungs can accumulate and flow back into the lungs- In either case, these infected secretions enter the lungs causing pneumonia.
All current systems and practices deal with methods of removal of these secretions from the area superior to the balloon (the subglottic region, i.e., between the glottis and the balloon placement in the trachea). This is done manually via syringe or a regulator valve connected to wall suction. Accumulations of infectious mucus in this area is obvious and its removal relatively easy. However, in the area inferior to the balloon, any coughed up mucus or mucus that bypasses the balloon tends to drain into the lungs and is not visible.
Also, in areas where dry air impinges on the trachea, mucins can dry and adhere to the trachea. Such local adhesions may be visible through a stoma port on the trachea but not through an endotracheal tube placed through the oral cavity. Anecdotal reports from nurses who deal with patients in coma and on a stoma/tracheal tube have noted the problem of visible localized adhesion of the mucus to the trachea. Such localized mucin adhesion is generally invisible to the caregivers (with the possible exception of what can be seen through direct stoma type tracheal ports) and pose a difficulty in locating and removal without a complete lavage. If the caked on mucins can be seen, they must be removed since they can become infected and flow back into the lungs.
As noted above, infected mucus that drains into the lungs is invisible to the health care team and does not show itself until some type of pneumonia sets in with its associated complications. In any case, visible or not, infected mucins mixed with liquid can drain into the lungs and is the probable cause of Ventilator Associated Pneumonia (VAP) and must be removed from the tracheal region by the care giver.
It should be noted that patients on assisted breathing apparatus (coma/ICU) might also have other medical complications. Thus, the problem of humidifying the intake air and maintaining the health of the trachea may be overlooked. However, as the effects and cost of VAP increase, hospitals and health care teams are beginning to pay serious attention to this issue and it will probably become more prominent.
The issue of ventilator associated pneumonia (VAP) has been recognized as a serious health issue by the Agency for Healthcare Research and Quality (AHRQ) and at the Centers for Disease Control (CDC). Because this type pneumonia is the result of hospital inattention, effective in 2012, Medicare has decided not to reimburse hospitals on simple symptom definition. Reimbursement will be based on patient outcome and, thus, hospitals will be burdened with the cost of controlling VAP.
VAP cost and consequences are not light. In extreme cases of VAP, a total lung lavage is considered appropriate. Total lung lavage—i.e., Bronchoalveolar Lavage (BAL), is a medical procedure in which an antiseptic fluid is regionally circulated through the lung. BAL is typically performed to diagnose lung disease and has been used to diagnose infections in people on mechanical ventilators with pneumonia—i.e., VAP. This is a very expensive and complex procedure requiring extreme care to prevent morbidity and mortality and is generally not used on already compromised patients.
There is therefore a need in the art for a tracheal/endotracheal device that, both, maintains a patient's airway and which also actively cleanses surrounding tissue areas of harmful mucins, secretions or the like—thereby preventing a build-up of the same. Such system may reduce the incidence of infection and pneumonia and ultimately, it may reduce the incidence of death by VAP.